Vehicle Routing Optimization Theory And Methods Based On Low-carbon Economy Perspective

Logistics is not only the source of energy consumption, but also the major source origin of Green House Gas (GHG) emission. With the trend of developing low-carbon economy among countries, green transportation and green logistics is an important and urgent issue. An abroad research study shows that:the transportation counts up to90%of total energy consumption in entire logistics actives. It has a significant value in theory and practice to investigate energy conservation in logistics with a vehicle scheduling aspect.This paper firstly reviewed the theory and practice of green logistics and vehicle routing problem in domestic and foreign, analyzing the factors of vehicle energy consumption and CO2emissions. Then the corresponding quantitative calculation and analyzing models on energy consumption and carbon emissions are described. Based on the above analysis, this paper investigated the vehicle routing optimization from the perspective of the low-carbon economy. The main research contents and innovations of this paper are as follows:(1) Research on vehicle routing problem with a single type under carbon emissionsAn optimization model is presented for the vehicle routing problem with a single type vehicle considering emission factor and the corresponding genetic algorithms is given. The results of simulation show that:when considering the factors of vehicle CO2emissions, the direction of routing plays great impact to the optimal solution. Namely, the different directions of the same path would be the two different levels of energy consumption and CO2emissions, as well as the total travel cost. Moreover, the shortest time routing is not necessarily the one of least CO2emissions, and not necessarily the lowest cost path. And the width of time window has a significant impact on vehicle operating costs.(2) Research on vehicle routing problem with multiple type vehicles considering CO2emissions An optimization model is presented for the vehicle routing problem with multi-type vehicles considering emission factor and the corresponding genetic algorithms is given. The findings discover that the hybrid type vehicles can improve the utilization efficiency of the ratio of vehicle loading. So compared with the single type scenario, the total distribution costs, energy consumption and CO2emissions are less. The advantage is more obvious considering service time window.(3) Research on green vehicle routing problem based on time-varying speed.Considering the impact of urban road congestion of vehicles, the speed piecewise change function with a ladder-type is provided according to the discipline of road vehicle speed variation. Based on the above analysis, an optimization model on green vehicle routing with time-varying speed is formulated. And the effective algorithm is given.The results of simulation shows that the choice of departure time has an important role in overall energy consumption and CO2emissions and the optimal travel time will save nearly8.5%of the CO2emissions than the worst travel time. Therefore, considering the efficiency of road traffic congestion, arranging departure times of delivery vehicle reasonably is an important measure of energy-saving and reducing logistics costs and CO2emissions.